Brake operating mechanism



Dec. 23, 1941. WQLF BRAKE OPERATING MECHANISM Original Filed April 15, 1935 INVENTOR.

ATTORNEY.

Patented Dec. 23, 1941 UNITED STATES PATENT? OF IC t i t 2,267,389 e L RAKE ornas'rmo MECHANISM Austin M. Wolf, Plainfleld, N. J.

-riginal application April 15, 1933, Serial No.

666,332. Divided and this application November27, 1939, Serial No. 306,300 r 3,Claims. (or. 188-204) This invention relates to brake operating illustrating an embodiment of the invention as mechanism, the subject matter [of thepresent application constituting a division of my pending application for patent, Ser. No. 666,332, filed April. 15, 1933, now Patent No. 2,181,161, November 28, 1939.

Theinyentionjmoreparticularly relates to the operation and control of fourwhe'el brakes for motor vehicles, and hasfor itsgeneral object and purpose to provide simple and efilcientlyoperating means for effecting a desired proportional distribution of, the braking effort between the front and rearpairs of wheel brake. mechanisms.

It is another object of theinvention in one embodimentthereof to provide brake actuating mechanism between an operator's brake pedal and the front and rearfpairsfdf wheel brakes ing system in, whichthe proportional distribution of the braking pressures is automatically varied by means of an inertia responsive device as disclosed in my pending application.

In a further embodiment of the invention, the brake pressure proportioning means is combined with a free wheeling deyice whereby when the vehicle motoris disconnected from the rear driving axle,proportionally greaterpressure is applied tothe braking mechanisms of the rear vehicle wheels. h h

With the above and otherobject in view,the invention consists in the improved brake oper atlng mechanism and in the form, construction and relative arrangement of its severalparts as will hereinafter bemorefully described,illus trated in the. accompahyinghrawing and subsequentlyincorporated in the subjoined claims.

In the drawing wherein I have illustrated several simple and practical embodiments of the invention and in which similar reference charfront and rear wheel brake mechanisms;

Fig. 2 is a detailhorizontal section illustrating a modified form of the adjustable equalizer.

Fig. 3 is a semi-diagrammatic side elevation applied toa vacuum booster braking system.

Fig. 4 is a plan view of the latter former the invention. c

Fig. 5 is a plan view showing another modified form-of the device applied to brake operat .13 system. r it Fig. 6 is a detail vertical section taken substantially on the line 6-E of Fig. 5, and t Fig. '7 is a plan view illustrating the combinationof the proportional brake pressure distributing meanswith a free wheeling control device for themotor vehicle. Referring in detail to the drawing, and for the present more particularly to Fig. 1 thereof, -5 and 6 respectively designate the longitudinal side rails of a motor vehicle frame orchassis, Tthe front axle and 8 the rear axis. said axlesbeing provided with the usual front and rear wheels 9 andzlll respectively, These wheels carry the brake drums indicated at I I'and I2 within which the braking mechanisms (not shown), of conventional type are mounted. The braking mechanisms may be either mechanically or fluid actuated, in accordance with common practice. In the particular application shown in Fig." l, of the mechanical type, the brake mechanismsare actuated, by the flexible connections I3 and M respectively to which power is transmitted through the rods I5 and I6 respectively from the.

front and rear brake shafts I1 and l8 which are suitably mounted at their opposite ends for oscillatory rotation upon the vehicleframeu It will be understood that the rear ends of the rods 15 are pivotally connected with upstandingarmsl 9 on the ends of the front brake shaft I! while the rods l6 are similarly connected with the downwardly extending arms '20 at the ends ofthe rear brake shaft 18.

At the rear of the vehicle dash indicated at 2|, the usual operator's brake pedalizis mounted upon a suitable supporting bracket 23 on the side rail 5 of the vehicle frame. A rod 24 is pivotally connected at its forward end with the lower end of said brake pedal that ir'ithe depression of said pedal, the rod will be moved forrespectively are pivotally connected at oneof a different type of their ends. The other end of link 3| is similarly connected to an arm 34 on one end of a sleeve 33 which is loosely mounted on the front brake shaft ll for oscillatory rotation relative thereto. The other end of this sleeve is also provided with an arm 35 connected by rod 36 with an arm 31 fixed to the rear brake shaft Ill. The other of the links 32 is connected at its forward end to an arm 38 which is fixed to the front brake shaft I1.

In the relationship of the parts as shown in Fig. 1, it will be evident that when pressure is applied to the brake pedal 22, the effort exerted thereon is conveyed to the equalizer bar 28 and equally distributed to the front and rear brake operating shafts l1 and I8 so that an equal braking effort is distributed to the front and rear wheel brakes.

In order to differentially proportion the braking effort between the front and rear wheel brakes, means is provided for rotating the trunnion- 25 so as to shift the point of connection of the rear end of rod 24 with the equalizer bar between the opposite ends thereof. One embodiment of this adjusting means may comprise a suitable lever 39 pivotally connected with the upper end of the trunnion 25. It is evident that when this lever is operated and moved to the position shown in dotted lines, the trunnion 25 will be rotated to position the connection 26 between said trunnion and rod 24 nearer to the end 30 of the equalizer bar than to the end 29 thereof thus transmitting a greater braking effort to the front brake applying shaft H. The upper end of the hub or boss 21 on the equalizer bar may be'provided with suitable notches as indicated at 40 in which the lever 39 has locking engagement to retain the trunnion 25 in its adjusted position. Of course, it is apparent that said lever can be actuated by suitable remote control connections with an operating element conveniently located with respect to the drivers seat.

For the purpose of effecting variation in the proportional distribution of braking effort in small increments, in Fig. 2 I show another form of the adjustable equalizer bar. In this case, said bar is in the form of a cylindrical rod 4| having suitably formed terminals 42 and 43 for connection with the links 3| and 32 respectively. Upon thisrod 4|, a sleeve 44 has threaded engagement upon the threaded section 45 of the rod 4|. To the front side of this sleeve the rear end of the rod 24 is adapted to be pivotally connected at 46. A lever 41 is pinned or otherwise secured at one of its ends to the equalizer rod 4| a vehicle having multiple front axles. Further, it is apparent that independent suspension of the vehicle wheels will in no way affect the operation of the invention. I have shown the invention as applied to a road vehicle, but, with resort to obvious modifications, the operating principles thereof may also be applied to the braking systems of rail-borne vehicles.

In Figs. 3 and 4 of the drawing, I show an application of the invention in connection with a vacuum braking system. For purposes of illustration, I show the prime mover or internal combustion engine 48 provided with a down-draft and is adapted to be manually operated through suitable connections therewith to rotate said rod, and thus shift the sleeve 45 so as to move the ,connection 46 with rod 24 from the central position illustrated in the drawing to a position in closer proximity to the end 43 of the equalizer. The terminals 42 and 43 of rod 4| are of the spherical form shown which permits of this axial rotation of rod 4| relative to the connections 3| and 32.

While in Fig. 1 of the drawing I have shown a four wheeled vehicle, it will be understood that the above described mechanism for proportioning the braking effort between front and rear brakes may also be applied to a six or eight wheeled vehicle. Should two rear axles be used, brake shaft l8 will apply the initial braking effort on the rear braking mechanism, and brake shaft |1 would function in the same manner for carburetor 49 connected with the intake manifold 50. The vacuum line 5| from said manifold is divided into the two branches 52 and 53, respectively, and vacuum is conveyed from these branch lines to the booster brake cylinders 54 and 55 respectively, for the operation of levers 56 and 51 connected with the brake actuating shafts 58 and 59, respectively.

A control valve indicated at 60 is interposed in the vacuum line 5| and forms an operating connection between the rods 6| and 62 the former being connected with brake pedal 22, and the latter with the equalizer bar 63 shown in Fig. 4. This equalizer bar divides the effort applied by the operators foot to pedal 22 between the arm 64 fixed to the front brake shaft 58 which is connected with one end of said arm by link 65. and the arm 61 on the inner end of sleeve 66 which is connected to the other end of the equalizer bar by link 68. Rod 69 connects arm 10 on the outer end of sleeve 66 with arm 1| fixed to the rear brake actuating shaft 59.

In Fig. 3 of the drawing, I have shown an automatic vacuum control means interposed in the branch lines 52 and 53. This means for controlling the vacuum supplied to cylinders 54 and 55 may be similar to that disclosed in my pending application above identified and comprises a slidable valve member within casing 12 having suitably formed ports therein to register with the pipe lines 52 and 53. One end of this slidable valve is connected with an inertia responsive pendulum mounted within the casing 13 so that in the initial application of the brakes and the resultant deceleration effect, in the responsive movement of said pendulum, the ports in the valve member will be relatively positioned with respect to the vacuum lines 52 and 53 so that a greater vacuum is produced in the front brake cylinder 54 than in the rear cylinder 55. Thus in proportion to the open areas of the respective valve ports in register with pipe lines 52 and 53 respectively, a proportionally greater braking effort will be applied to the front 'wheel' brakes than to the rear brakes.

It will be readily seen that in the above con,- struction, normally the proportional distribution of the braking effort upon the front and rear brakes will be automatically effected by the operation of the inertiaresponsive control valve. However, in the absence of a vacuum in the braking system, when the engine stalls Or for other reasons is not operative, the manually applied pressure on brake pedal 22 will be equally distributed to the brake actuating shafts 5B and 59 by the mechanism illustrated in Fig. 4 of the drawing. However, this latter condition is exceptional and rarely occurs.

In Figs. 5 and 6 of the drawing I have illustrated an application of the inertia responsive means for proportionally increasing the braking effort on the front brakes in connection with a rod I8 with the conventional operators brake pedal and actuates the valve control ,rods 80 and 8| respectively. Each of these rods is connected with one end of the equalizer bar bypins 82 and 83 respectively, equi-distantly spaced from the clevis connection 84 between said bar and the rod 18. The piston in cylinder 14 is connected with the vertically spaced bars 85 and 86 disposed in parallel relation respectively above and -below the rod 80. These bars extend rearwardly of the equalizer bar 18 and are pivotally connected as at 81 with the brake actuating rod 88 which controls the application of the rear vehicle brakes. I

Similar vertically spaced bars 88 and 80. are

connected with and actuated by the piston in cylinder 15 and are connected attheirrear ends as at III with the actuating rod 92 for the front vehicle brakes.

The pins 82 and 83 are movable relative to the pairs of bars 85, 86 and 89, 80 respectively, for which purpose each pair of bars is provided with openings 83 and 84 respectively of relatively large diameter. This clearance between said pins and the bars connected with the pistons in cylinders Hand I permits movement of the valve rods 80 and 8| and the valves connected therewith upon initial movement of the equalizer bar I8. Air is thus admitted to the rear ends of cylinder I4 and 15, causing a forward movement of the bars 85, 86 and 88, 80' which transmit. brakeapplying movement to the rods 88 and 82. I

A spring 85 bearing against disk 86 on rod 80 yieldingly holds the valve of cylinder 14 in its normal position. The clearance openings 83 in the bars 85 and 86 permits movement of the brake cylinder piston in correspondence with the position of the foot on the operators brake pedal to increase the pull on the brake rods, or to hold them stationary, depending upon whether the depression of the brake pedal is continued or said pedal held in a definite position.

A spring 81 also holds the valve of cylinder 15 in its normal position, said spring bearing against an inertia responsive mass.88 fixed to the valve rod 8| by pin 88. This mass moves freely along the bars 89 and 80, except as restrained by the spring 81. Under the influence of inertia, such as ocurs in braking the vehicle, the mass 98 will slide forwardly, thus actuating the valve of cylinder I5 to admit fluid pressure to said cylinder '50 that the said cylinder through 'the connections withrod 92 will, due to the influence of inertia,'produce a greater braking effort on the front brakes of the vehicle than that which is produced upon the rear brakes by cylind8! 14. f

The usual method of braking a motor vehicle consists in utilizing the engine braking effort by not declutching until the vehicle has reached a very low rate of speed. However, with the use of free wheeling, in the operation thereof the driving power developed by the engine is not transmitted to the rear driving axle so that the braking effort of the engine on the rear vehicle wheels is not available. Accordingly, it is apparent that there is a material difference between the proportional distribution of the braking effort to the front and rearwheels when the brakimpossible. I

In Fig. 7,0f the drawingIhave shown an application of the present invention which operates to increase the braking effort on the rear wheels when free wheeling is in use in approximate proportion to the braking effort of theengine when the free wheeling unit is locked out of operation. As shown, the operator's brake pedal 22 is connected by rod 24 with a block I00 which is axially shiftable along the equalizer bar IOI. The ends I02 and I03 of this bar are connected respectively by rods I04 and I05 withthe arms I06 and I01 on the front and rear brake shafts I1 and I8 respectively; In the position shown in the drawing, the block or member I00 is nearer the end I03 than the end I02 of the equalizer barHDI. Accordingly, a greater braking effort will be transmitted through rod I05 to the rear brake shaft I8 to compensate for inaction of the engine during the free wheeling.

At the rear end of the power transmission unit I08, the free wheeling cam I08 drives the member H0 on the universal joint shaft III which is connected by the usual propellershaft with the differential drive of the rear wheel axle. A slidable member H2 has means for locking engagement with the member H0 so as to connect the latter through the transmission with the power shaft of the engine when free wheeling is not desired. In the disengaged position shown in the drawing, the free wheeling action is in use. In order to lock out the free wheeling unit, the operator moves lever H3 in a counter-clockwise direction to rock shaft H4 having an arm II5 connectedby rod H6 with one end of the This lever is fulcrumed intermediate lever III.

of its ends atI I8 and the other end thereof is operatively connected with member H2 whereby said member is shifted into clutching engagement with the member H0.

, A second arm H8 on rock'shaft H4 is con nected to the flexible cable I20 movablethrough a suitable guide casing I2I mounted in spaced supports indicated at I22 and connected at its other end to the slidable block I00. Thus it will be evident that when member H2 is clutched to the member H0 and free wheeling is notin use, the block I00 is simultaneously shifted.to-

wards the center of the equalizer bar MI by the operation of lever H3, thereby reducing the braking effort applied to the rear vehicle wheels through the operation of the pedal 22.

From the foregoing description considered in connection with the accompanying drawing, the construction, manner of operation and several advantages of the described embodiments of the invention will be clearly understood. It will be seen that I have provided in a very simple mechanical construction, a brake operating mechanism which is capable of practical application to meet different conditions which may arise in the operation of the vehicle and which includes means for distributing the braking effort to the front and rear wheel brakes in proper relative proportions to most efficiently, quickly and safely effect deceleration of the vehicle speed and bring the vehicle to a stop. Of course, the examples of the adjustable equalizer and actuating means therefor which I have above described,

are largely suggestive, and other alternatives therefor will suggest themselves to one versed in the art. It is accordingly to be understood that while I have herein disclosed a number of-simple and practical applications of my present improvements, the essential features thereof may also be exemplified in various other structural forms and relative arrangement and combination of the several cooperating elements. Therefore, the privilege is reserved of resorting to all such legitimate modifications in the above respects as may fairly be considered to be within the spirit and scope of the appended claims.

I claim:

1. Vehicle brake operating mechanism, comprising spaced brake applying members operatively connectedwith front and rear brakes respectively, operator controlled means for actuating said members including an equalizer bar, a rotatable member mounted on the equalizer bar, a brake pedal, an operating member connected at one end to said pedal and having its other end eccentrically connected to said rotatable member, connecting means between the opposite ends of said bar and the respective brake applying members, and means for actuating said rotatable member to position the connection with said operating member relative to the ends of the equalizer bar and variably proportion the distribution of braking effort to the front and rear brakes.

2. In vehicle brake operating mechanism, front and rear brake actuating shafts, an equalizer bar, operating connections between the opposite ends of said bar and the respective brake operating shafts, a manually operable brake applying member, and a member rotatably mounted on the equalizer bar with its axis perpendicular to the plane of said bar and eccentrically connected with one end of said brake applying member to position the latter relative to the ends of the equalizer bar and variably proportion the distribution of braking efiort to the front and rear brakes.

3. In vehicle brake operating mechanism, front and rear brake actuating shafts, an equalizer bar, a relatively oscillatable sleeve mounted on the front brake actuating shaft, means operatively connecting one end of said sleeve with the rear brake actuating shaft, an actuating connection between one end of the equalizer bar and the other end of said sleeve, means operatively connecting the other end of the equalizer bar with the front brake actuating shaft, a member rotatably mounted on said equalizer bar intermediate of its ends, and a manually operable brake applying member operatively connected with said rotatable member by means acting to variably position said brake applying member betweenthe ends of the equalizer bar upon rotation of said rotatable member to proportionately distribute the braking effort between the front and rear brakes. g

. AUSTIN M. WOLF. 

